In recent years music or video delivery or distribution over the Internet has become popular. In some cases, the music or video is streamed to interested persons. In other cases, electronic media files are downloaded to interested persons. The electronic media files being downloaded might be encrypted to prevent further unauthorized distribution. When the electronic media files are encrypted, the interested persons are also provided with appropriate cryptographic keys so that the encrypted media files can be decrypted. Once decrypted, the media content within the electronic media files can be played for the interested persons. However, once an electronic media file is decrypted, there is no non-intrusive way to conventionally ensure what portion the interested person has watched. Typically, nothing prevents the interested person from skipping playback of certain portions of the electronic media file that are of less interest to the interested person.
Thus, there is a need for improved approaches to control playback of electronic media files on a media playback device.